Tried the gregtech.log File? They should never just disappear, so what do your Players define as disappear? Turning Invisible but still being there, or turning into Air? What is the surrounding Area around them?

Hi Shuishan, were you able to find out more information from your players?

Did the machines turn invisible but could still be touched/jumped on or could you walk through them?
were the outside or inside?
Did it happen when they logged off and on, or did they disappear while they were watching them?
Did they explode?

Hi Shuishan,
did they maybe try to move a Gregtech Tileentity through some mod?
I once tried moving a Gregtech hopper with a Levitational Locomotive from Thaumic Tinkerer and that caused them to just vanish. I did not check the Gregtech logs thought.

I sadly dont know what KCauldron screws up with it. The whole System of placing GT6 Blocks is very complicated and not really something that any external Code should ever mess with at all, considering it’s already almost impossible to make it work with vanilla Minecraft without hackery.

And I cant just use the “normal” way because then we would run out of Block IDs.

So unless I get much more details on what exactly is happening, I cannot really help. : /

Hello!
Also, the blocks disappear on my server.
The server is local, we play only with a friend.
KCauldrone 1.7.10-1614.201
gregtech_1.7.10-6.11.04

All the missing blocks are tileentity: bushes with berries, pipes, mechanisms and others. In all cases, the environment is different, as is the position in the chunk: only grass is nearby - below, a wall nearby or something else.
I did not find anything in the logs.